linux-kernel - [PATCH 1/1 linux-next] fs/affs: bugfix: make symbolic links work again

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Date:   Sat, 15 Apr 2017 08:54:36 +0200
From:   Fabian Frederick <fabf@...net.be>
To:     Andrew Morton <akpm@...ux-foundation.org>
Cc:     Duane Griffin <duaneg@...da.com>,
        Alexander Viro <viro@...iv.linux.org.uk>,
        linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
        fabf@...net.be
Subject: [PATCH 1/1 linux-next] fs/affs: bugfix: make symbolic links work again

AFFS symbolic links were broken since kernel 2.6.29

Problem was bisected to the following

commit ebd09abbd969 ("vfs: ensure page symlinks are NUL-terminated")
commit 035146851cfa ("vfs: introduce helper function to safely
NUL-terminate symlinks")

AFFS wasn't setting inode size when reading symbolic link from disk or
creating a new one. Result was zero allocation in pagecache.

ln -s file symlink

ls -lrt

file
symlink ->

This patch adds inode isize information on inode get and symbolic link
addition.

Signed-off-by: Fabian Frederick <fabf@...net.be>
---
 fs/affs/inode.c | 1 +
 fs/affs/namei.c | 1 +
 2 files changed, 2 insertions(+)

diff --git a/fs/affs/inode.c b/fs/affs/inode.c
index abcc598..fd4ef3c 100644
--- a/fs/affs/inode.c
+++ b/fs/affs/inode.c
@@ -140,6 +140,7 @@ struct inode *affs_iget(struct super_block *sb, unsigned long ino)
 		inode->i_fop = &affs_file_operations;
 		break;
 	case ST_SOFTLINK:
+		inode->i_size = strlen((char *)AFFS_HEAD(bh)->table);
 		inode->i_mode |= S_IFLNK;
 		inode_nohighmem(inode);
 		inode->i_op = &affs_symlink_inode_operations;
diff --git a/fs/affs/namei.c b/fs/affs/namei.c
index 96dd1d0..b02da4d 100644
--- a/fs/affs/namei.c
+++ b/fs/affs/namei.c
@@ -365,6 +365,7 @@ affs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
 				symname++;
 	}
 	*p = 0;
+	inode->i_size = i + 1;
 	mark_buffer_dirty_inode(bh, inode);
 	affs_brelse(bh);
 	mark_inode_dirty(inode);
-- 
2.9.3